Central retinal vein occlusion with cillioretinal artery occlusion in hyperhomocysteinemia

Description

A healthy 27-year-old man presented with blurring in his right eye for 1 day. The left eye was normal. Visual acuity was 6/24 in the right eye with normal anterior segment. Fundus examination of the eye revealed mild disc oedema, retinal venous dilation and tortuosity and multiple retinal haemorrhages (figure 1A). A well-defined area of retinal whitening was seen in the macular area. Fluorescein angiogram (figure 1B) showed delayed venous filling and identified the cilioretinal artery (red arrow, figure 1B). A diagnosis of right eye central retinal vein occlusion (CRVO) with cilioretinal occlusion (CLAO) was made. Thorough systemic investigations and cardiac evaluation revealed no abnormality, but raised levels of serum homocysteine (23.2 µmol/L) were noted. The patient was advised intravitreal bevacizumab for macular oedema, in addition to vitamins B₁₂, B₆ and folic acid. At 1-month follow-up, the macular oedema had resolved and vision improved to 6/9.

Figure 1.

Fundus photograph of the right eye of the patient showing mild disc oedema, retinal venous dilation and tortuosity, scattered retinal haemorrhages, and well-defined area of retinal whitening between the disc and macula (A). Fluorescein angiogram of the right eye (B) showing area of hypofluorescence in relation to retinal whitening and normal filling of the cillioretinal artery (red arrow).

CRVO in a patient older than 60 years of age with known systemic vascular risk factor does not warrant systemic work up. In a young patient with CRVO, however, an initial work up should consist of blood pressure, lipid profile, plasma glucose levels, erythrocyte sedimentation rate, antinuclear antibody and antiphospholipid antibody.

Hyperhomocysteinemia is an independent correctable risk factor for vascular disease and is a recognised risk factor for CRVO in young patients.¹ CLAO in the setting of CRVO is due to transient haemodynamic blockage resulting from increased pressure in the retinal capillary network.²

Learning points.

• Hyperhomocysteinaemia is an important cause of central retinal vein occlusion (CRVO) in young patients and should be a part of systemic work up in such patients.

• Cillioretinal artery occlusion in the setting of CRVO is more of a physiological block than actual blockage of a blood vessel.